A DIAGNOSTIC BALANCE MODEL FOR STUDIES OF WEATHER SYSTEMS OF LOW AND HIGH LATITUDES, ROSSBY NUMBER LESS THAN 1

Abstract

This paper outlines a theory for a diagnostic balance model. A unique manner of partitioning baroclinic vertical motions into various forcing mechanisms is proposed as a natural extension of the quasi-geostrophic problem. Forcing functions include advection of vorticity and temperature by the nondivergent and the divergent part of the wind. Role of various terms of the complete vorticity and the so-called balance equations are included in the analysis. Other features of the diagnostic model are air flow over terrain, frictional contributions at the lower boundary, sensible heat transfer from water surfaces, and stable and unstable formulations of latent heat release. Typical magnitudes and physical interpretations of several nongeostrophic mechanisms are illustrated. Two applications of the above mentioned diagnostic model appear in this issue, a study of a frontal cyclone development by Krishnamurti and a study of a low latitude disturbance by Baumhefner.